Fluid samples are often collected for diagnostics testing including, by way of example, “drugs of abuse” testing, hormone replacement therapy, other diagnostics and clinical testing including HIV screening, environmental sampling, veterinarian sample collection and other similar applications. The substances collected are varied and include, for example, bodily fluids such as saliva, blood, urine, surface moisture from any type of surface including exterior body surfaces, or any other type of fluid that is typically subjected to diagnostics testing.
It is a common practice to use a swab of absorbent material as a collection medium. The swab is often mounted on an end of a collection stick and is supplied in a kit that also contains a container or vial into which the swab and sample are placed for purposes of transportation or analysis. The vial may contain a buffer solution into which the swab with the sample is submerged.
To collect a sample, the swab is brought into contact with the fluid sample to be collected to transfer the sample to the swab. The swab is then placed in the vial and submerged in the buffer solution. There are many variations in the subsequent sample collecting process depending on how the collected sample is to be analyzed. For example, in some applications, the sample is analyzed contemporaneously with it being collected, and that process may be carried out in the vial or a contiguous container. However, in other applications, the vial with the collected sample is sealed and sent to a different location for subsequent analysis.
With known sample collection systems in which a collected sample is to be shipped to a location for analysis, it is known to seal the swab and the collection stick in the vial for transportation to the location of analysis. At the location of analysis, a technician typically uses the collection stick to compress the swab against the bottom of the vial to extract or express the sample from the absorbent swab into the buffer solution. The swab is then removed from the vial and may be discarded. A pipette or other instrument is then introduced into the vial to remove a mixture of the fluid sample and buffer solution from the vial for analysis.
However, it will be appreciated that if the swab is not sufficiently compressed in the vial by the technician to express the sample from the swab, the integrity of the analysis may be compromised. Moreover, requiring the technician performing the analysis to extract the sample from the swab generally increases the cost and complexity of the analysis process and also risks contamination of the sample while the collection stick is being handled.
A sample collection system has recently been developed that overcomes many of the drawbacks and shortcomings of known prior systems for collecting a sample from an absorbent. That sample collection system, described in U.S. Publication No. 2007/0208274, includes a vial and a collection stick. The vial has a wall defining a closed end and an open end and may be configured to contain an optional buffer solution within the vial. A cap is provided to selectively seal with the open end of the vial.
The collection stick has an elongated handle portion and an absorbent head portion detachably connected to the handle portion. The absorbent head portion is configured to absorb and retain the fluid sample within the absorbent head portion prior to insertion of the collection stick within the vial.
The vial wall and the absorbent head portion are configured to permit insertion of the collection stick into the vial so that the absorbent head portion is compressed against the closed end of the vial to express the fluid sample from the absorbent head portion and mix with a buffer solution within the vial if the buffer solution is present within the vial. The elongated handle portion is detached from the absorbent head portion and removed from the vial while the absorbent head portion is retained in a generally compressed state within the vial.
While the sample collection system described in U.S. Publication No. 2007/0208274 overcomes many of the drawbacks and shortcomings of known prior systems for collecting a sample from an absorbent, there is a continuing need for a sample collection system that simplifies the extraction of a fluid sample from an absorbent for subsequent analysis of the sample. There is also a continuing need for a sample collection system that assures proper mixing of a fluid sample and buffer solution within a vial for accurate analysis of the sample, with minimal loss or contamination of the sample during the collection process.